Three fundamental processes regulate burial and preservation of organic matter in the sedimentary record and thus of organic carbon. These processes are dilution, production and decomposition. The impact of these processes can be modified by the rate at which they occur.
Rocks, via outcrop, cores, core chips, plugs, cuttings, or other, can be analyzed by geochemical methods to determine the geochemistry and hydrocarbon potential in rock formations or units of interest. The rocks, cores, cutting, core chips, etc. can be further studied using stratigraphic methods to determine a history of deposition of sediments (stratigraphic sequence). The geochemical methods and the stratigraphic methods can be used together to evaluate the likely presence and concentration of total organic carbon and its mode of deposition within a basin. Conventional methods have used each of the geochemical and stratigraphy methodologies independently. However, each method alone provides only a limited insight as to how or where potential organic carbon is present in the rock formation of interest.
The following paragraphs describe an integrated stratigraphic methodology that incorporates both the geochemical methods and the stratigraphic methods and the inter-dependencies between them, thereby allowing the construction of depositional models through geologic time that provide a more complete insight as to how and/or where potential organic carbon rich sediments will have accumulated within a hydrocarbon basin.